using System;
using System.Collections.Generic;
using System.Linq;
using Chernobyl.Destruction;

namespace Chernobyl.Unity.Event
{
    /// <summary>
    /// Holds subscriptions from one <see cref="IObservable{T}"/> to multiple <see cref="IObserver{T}"/>
    /// instances. Useful with dependency injection.
    /// </summary>
    public class Subscriptions<T> : IDisposable
    {
        /// <param name="observable">The observable to subscribe the <paramref name="observers"/> to.</param>
        /// <param name="observers">The <paramref name="observers"/> that are to be subscribed to
        /// <paramref name="observable"/>.</param>
        public Subscriptions(IObservable<T> observable, IEnumerable<IObserver<T>> observers)
        {
            _disposables = observers.Select(observable.Subscribe).ToArray();
        }

        /// <inheritdoc />
        public void Dispose() => _disposables.Dispose();

        readonly IDisposable[] _disposables;
    }
}